The bridge district has hired Oakland-based consultant AECOM for roughly $1 million to design the gantry, which will be built south of the existing toll plaza. The entire project will cost about $7 million.

“The technology we have at the toll plaza was put in two years before the first iPhone was put out,” said Denis Mulligan, general manager of the bridge district. “That gives you an idea about how dated the technology is.”

In 2000 the FasTrak electronic toll system came online at the bridge’s toll plaza. At the time toll takers still worked at the span and drivers had the option of paying with cash or electronically. Because there were two functions, the FasTrak equipment was hard-wired into the toll booth structure.

But in 2013, toll takers were eliminated in a cost-cutting measure and in the passing years the FasTrak equipment has become outdated. Additionally, the cameras, lights and other FasTrak equipment has become the unintended target of vehicles crashing into the apparatus in the plaza’s narrow lanes. The state is also developing new rules for electronic toll systems that the span’s current equipment doesn’t meet.

Rather than put new equipment in the old toll plaza, bridge officials are looking to erect a gantry by Jan. 1, 2019.

The gantry will have motion sensors, antennas, lights and cameras to assess tolls. That puts most equipment above the roadway, allowing maintenance to occur without lane closures.

“The limited vertical clearance and configuration of the existing toll booths structure cannot support the new technology, so a new support structure is required,” reads a report on the gantry.

The new support structure will be a single steel gantry supported by concrete foundations, located approximately 200 feet south of the toll booths and spanning over all southbound lanes. About 20 million cars pass southbound over the span each year. AECOM was hired last month to design the structure.

While sophisticated, the new equipment would not be able to count passengers, keeping the three-person carpool regulations somewhat on the honor system, although enforced by the California Highway Patrol.

There are no plans for the existing toll plaza. That will part of a separate project that has not entirely come into focus. For now, that means the art deco clock at the span will keep its home.

“But at some point we may look to reconfigure the toll plaza,” Mulligan said, adding the clock would remain at the span if that occurred.